1. Field of the Invention
The present invention relates to vehicle air conditioners.
2. Description of the Prior Art
FIG. 1 shows an air conditioning system widely used in modern automotive vehicles. In the figure, the reference numeral 1 indicates a case forming therein an air flow passage 2. The case 1 is formed at an end thereof with an inlet 3 and at the other end thereof with a defroster outlet 4, ventilator outlet 5 and floor outlet 6. Within the air flow passage 2 there are disposed a blower 7 and an evaporator 8 and further disposed downward thereof a heater core 9 for action as a heat exchanger and an air-mix door 10 for controlling air flow through the heater core 9 and thereby controlling the temperature of air blown from the above mentioned outlets 4, 5 and 6. The air-mix door 10 is turned in the direction "A" when the above mentioned temperature is desired low and in the direction "C" when the temperature is desired high and is placed adjacent the position "B" when the temperature is desired moderate.
The heater core 9 and the air-mix door 10 are controlled by a drive mechanism as shown in FIG. 2. In the figure, the reference numeral 11 indicates a shaft which is rotatable together with the air-mix door 10. An end of the shaft 11 is connected through a link 12 to an actuator 13 whose operation is controlled by a solenoid valve 14. The heater core 9 is communicated with a water jacket of an internal combustion engine, not shown, through an inlet pipe 15a and outlet pipe 15b. The inlet pipe 15a has disposed therein a water cock 16 for controlling the flow rate of engine coolant supplied therethrough to the heater core 9. To this end, the water cock 16 is operatively connected through a link 17 to an actuator 18 whose operation is controlled by a solenoid valve 19. The temperature blown from the outlets 4, 5 and 6 is thus adjusted to a set value by controlling the air-mix door 10 and the water cock 16 through operation of the actuators 13 and 18 in accordance with the set temperature.
With the prior art arrangement, two actuators 13 and 18 are required for independently controlling the air-mix door 10 and the water cock 16. Due to this, adjustment of the actuators 13 and 18 is necessitated after their installation for timing their operations to each other for thereby timing the operations of the air-mix door 10 and the water cock 16 to each other, resulting in a necessity of a difficult and time-consuming adjusting work.
Further, with the above prior art arrangement, a plurality of actuators 13 and 18 and a plurality of solenoids 14 and 19 are indispensable, resulting in an expensive manufacturing and assembly cost, a necessity of a wide space for arrangement of such parts and a possibility of providing an increased limitation to the design of the associated parts.